Some alternatives that you can use is to replace the sugar with Stevia or other baking sugars that are sugar replacement. I stopped purchasing regular white sugar some years ago. I either get organic sugar or some of the sugars that are more brown in color and coursers, so you have to mix well when using them.
This recipe is for individual dishes, but I also do this as a bigger pie. I have done it for so long that I don't have the actual amount of the ingredients, I tend to look at it for the consistency I want. I like the crust to be more oatmeal than flour. If you make it let me know what you changed or if you used it as it was. I actually liked the tart and sweet with the oatmeal. Enjoy!